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lfiondella / SRT

Software Reliabilty Testing
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Times to Next N Failures on Tab 3 Doesn't Converge for Large Values of N in Geometric Model #72

Closed a1729nikora closed 8 years ago

a1729nikora commented 8 years ago

When doing the detailed queries in Tab 3, specifying a large number of failures in the "How much time will be required to observe the next N failures" input area will result in the solution for the Geometric model to not converge if N is sufficiently large. For example, using SYS1 as the data set, setting N to 21 will return an "NA". This shouldn't happen, since the Geometric model is an infinite-failures model.

a1729nikora commented 8 years ago

Corrected situation in which Geometric model returns values
of “NA” when large values of N are specified in Tab 3’s “How much time will be required to observe the next N failures” input area. This was done by putting tighter bounds on the solution search interval in “Detailed_predictions.R” function “est_t”.

Simplified the equation in “GM_MVF_cont” in “GM_BM.R” to reduce computation time.